Abstract
The crystal structures of the title compounds [SO (TMSO), SO (DMSO)] have been determined. The TMSO salt is orthorhombic [space group , , , and Å] while the DMSO salt is monoclinic [space group , , , Å, and ]. Each contain linear chains of Cu ions with three bridging ligands (2 C1, 1 O) between each pair of Cu ions. The bridging Cu--Cu angles are ∼ 87° for the symmetrical bridges and ∼ 80° for the asymmetrical bridges. In each salt, the copper coordination geometry is severely distorted from octahedral with four short Cu-ligand bonds (three chlorine and one oxygen) and two long Cu-ligand bonds (one chlorine and one oxygen). Adjacent chains are well isolated from each other by the sulfoxide groups in one direction, but short sulfur-sulfur contacts occur between adjacent chains in the other direction. The susceptibility of the salts has been measured between 2.0 and 300 K on a PAR vibrating-sample magnetometer and on a Faraday balance. The high-temperature data show positive deviation from Curie behavior, indicative of ferromagnetic coupling. However, considerable magnetic interactions between chains exist and the vs plots show maxima at low temperature. The data have been analyzed with several one-dimensional models. The best fit is obtained with an Heisenberg linear chain with ferromagnetic interaction (K, TMSO; K, DMSO) with a mean-field correction for the antiferromagnetic interchain interactions (K, TMSO; K, DMSO). Thus, the relevant ratio defining the ideality of the system, , is ∼ 50 for the TMSO salt and ∼ 25 for the DMSO salt.
- Received 7 August 1978
DOI:https://doi.org/10.1103/PhysRevB.20.2154
©1979 American Physical Society